Repurposing an A123 Prius brick (616x 26650A cells)

[brewmium]

Soldering nickel strips to nickel strips should be pretty easy.

I totally agree!

Like 3 of those packs together would make 2 individual 3.2v cells. That way you'd use 12 out of your 14 packs

I like the way you think! And, i can always use the left overs on something... or as a backup.

 

[brewmium]

Since you don't have the exact # of those packs you'll need for your 24v setup, I was thinking of maybe tying those packs together with the nickel busbars... Like 3 of those packs together would make 2 individual 3.2v batteries. All cells facing one way will be one 3.2v battery, and all facing the other way would be another...which may make for less criss-crossing? That way you'd use 12 out of your 14 packs, and have two left for spares. It's tough to give advice like that without seeing and handling them up close, but it seems like you have the knowledge to clearly handle that on your own.

Getting back to this, now that i am less overwhelmed by the real world, and back to processing this and responding. I have both questions, and ideas.

First, 3s of this cell is what i am looking for? Then 8 of those to get my 24v? For some reason I had it in my head all of this stuff liked to run over voltage, and that out would be 4s. Which, with these awesome little packs, even with some criss-crossing, stand nicely together... that is if need to use all 4 quarters of 11p.

Starting to tie them together, just sounded like it was going to get messy. I'm not sure how i'd buss bar between them, but, i guess with the 1/8th inch plastic covering them, a nickel buss bar could run between them, then i'm talking a completely different kind of container that if they were just all independent with nice lugs on the tops.

If i need to be making corners, will I switch some stout copper? I have 10' of 2/0 gauge copper for the controller to inverter, with most all left over.

Thanks for any wisdom!
-eric

 

[SolarRat]

My description was hard to follow. Not 3s, just using 3 of those packs together to make two 3.2v "batteries". They'd be one block but have two seperate outputs to send to the next 3 pack...4 of these three packs will have 8 total 3.2v "batteries" which would then be connected in series for 24v. If you can place two sets of these three packs side by side you might be able to tie them into one 6 pack with 4 "batteries" for 12v, then stack another 6 pack on top for 24v. It won't be pretty or easy, but would make the most out of your 14 packs...

You could put lugs on each 3 pack and use jumper wires to connect them all IF using multiple busbars wasn't an option. Without looking at it all I can do is throw out suggestions, but you'll have to determine what's feasible for you without ruining an already nice pack.

 

[brewmium]

It’s been a few days, but I am just about ready yo make some cuts in the existing nickel, and solder some new paths. I managed to plan it out with ZERO nickel overlaps!! I’ll post some pics, and also show how cool the packs are!! They will fit together in ANY orientation, which I thought was really cool.

So... anyone care to point me to what to buy for a balancing thingy for the charge side?

 

[brewmium]

I found it, the BMS. Hope it arrives from China. :-/ does anyone know where you can get an 8s 100a LiFeP04 BMS already in the states?

 

[Buzz Powers]

Nope, they should be LiFePO4 so 12.8 would be full... A123 nanophosphate SHOULD be right... I wish more info was on them.

See the attachments. Just a bit out of order, watch for pages 1 thru 4. Filled with good info.
I have been testing 40p 8S 24v Nanophosphate system since March of 2020 with 550watt PVs and a 20amp mppt CC. It likes to stay around 27.2volts or 3.45v each and very little advantage going to 3.6. There is very little wattage used before it drops 26.4. So, 3.3 really is optimal. Charging from 2.7 to start up to 3.7 measures to the rated 1350 mil amps.
Just completed the big brother of 160p 8S battery I plan to launch this March.

 

[Buzz Powers]

See the attachments. Just a bit out of order, watch for pages 1 thru 4. Filled with good info.
I have been testing 40p 8S 24v Nanophosphate system since March of 2020 with 550watt PVs and a 20amp mppt CC. It likes to stay around 27.2volts or 3.45v each and very little advantage going to 3.6. There is very little wattage used before it drops 26.4. So, 3.3 really is optimal. Charging from 2.7 to start up to 3.7 measures to the rated 1350 mil amps.
Just completed the big brother of 160p 8S battery I plan to launch this March.

Well, I just put my 5kw Nano Phosphate 8S 24v into service. The pic was taken 2 days ago after I topped off their charge I hooked them up in parallel for about a day.

 

[Buzz Powers]

Well, I just put my 5kw Nano Phosphate 8S 24v into service. The pic was taken 2 days ago after I topped off their charge I hooked them up in parallel for about a day. View attachment 40585

Here is some of the tech data from the manufacturer.